1. Field of the Invention
The present invention concerns a hydraulic system having at least one hydraulic valve for actuating a component, where a control pressure acting on the hydraulic valve can be activated through a supply pressure of a pilot circuit having at least one actuator.
2. Description of the Related Art
Such a hydraulic system is sufficiently known from vehicle technology, for example for actuating transmission components. The hydraulic circuit, which is usually coupled with a pilot circuit, as a rule has one or more proportional and/or on/off valves as actuators, which to set a control pressure at the hydraulic cylinder produce a leakage which is carried off to a connected tank. The leakage produced by the respective actuators, which are generally in the form of electromagnetic valves, is dependent on a pilot orifice used in the pilot circuit and on the flow conditions in the actuators.
It has been found that the leakage produced increases to a not insignificant volume, in particular when several electromagnetic valves are used. Hence, among other things, a correspondingly larger capacity pump is necessary to return the leakage flow.
Accordingly, an object of the present invention is to provide a hydraulic system of the type named at the beginning, wherein the leakage is reduced without diminishing the dynamics of the hydraulic system.